Ring-Opening Polymerization of 3,6-Dimethyl-2,5-Morpholinedione with Discrete Amino-Alkoxy-Bis(phenolate) Yttrium Initiators: Mechanistic Insight

International audienc

Bis[bis(oxazolinato)] Complexes of Yttrium and Lanthanum: Molecular Structure and Use in Polymerization of (D,L)-Lactide and (D,L)-Γ-Butyrolactone

International audienc

Syndiotactic-Enriched Poly(3-hydroxybutyrate)s via Stereoselective Ring-Opening Polymerization of Racemic b-Butyrolactone with Discrete Yttrium Catalysts

International audienc

Accelerated syntheses of amine-bis(phenol) ligands in polyethylene glycol or “on water” under microwave irradiation

Pure amine-bis(phenol) ligands are readily accessible in high yield, often >90%, when the Mannich condensation reactions are performed “on water” or in poly(ethyleneglycol) (PEG). Microwave-assisted synthesis dramatically reduces the time and energy required to prepare these molecules, typically from 24 h to 5 min. The approach seems to be widely applicable (7 amines and 5 phenols were tested to yield a diverse set of bis(phenol) ligands). Significant improvements in yield were observed for ligands derived from di-tert-amyl and di-tert-butyl phenols, possibly resulting from a hydrophobic effect. Single crystal X-ray diffraction data for the ligand derived from p-cresol and N,N′-dimethylethylenediamine is reported